Clamping device for a piesoelectric actuator of a fuel injection valve for internal combustion engines

A fuel injection valve for internal combustion engines, having a valve member (9) which is guided so that it moves axially in a valve body (1) and includes a sealing face (11) provided on a combustion chamber end face to open and close a valve seat for passage of a fuel to an injection opening (15) on the valve body (1) a piezoelectric actuator that includes a piezoelectric stack (23), said piezoelectric stack changes in length with application of a control voltage, said piezoelectric stack is coupled to an end of the valve member (9) to actuate the valve member, a valve spring (27) acts upon the valve member (9) in a closing direction, a clamping device (37) formed of a piezoelectric material that includes an operative means is provided on the piezoelectric actuator and fixes an end of the piezoelectric stack (23) remote from the valve member (9) in an axial position during the injection phase of the fuel injection valve, and permits an axial compensation for play at the piezoelectric stack (23) during an injection pause, and the clamping device (37) has a clamping ring (39) made of piezoelectric material, which encompasses a shaft of the piezoelectric stack (23) and whose inner diameter is reduced when said clamping ring is acted upon by an operating voltage.